Mesh Bed Leveling Fails - Bed gets stuck
Dear Community,
I´m facing a problem, and maybe you can help me to solve it. An official answer via e-mail is still pending, but I´d like to share it with you, so maybe in the future it will help other people.
I´ll try to make it short with the essential information:
-MK2 Kit 3D pinter is assembled according to the handbook
-Newest firmware (3.0.8)
-Selftest is okay
-Calibrate Z is also okay
-Calibrate XYZ is okay
Here is the problem:
-Once Auto Mesh Bed Leveling is run, the printer starts to look for the 9 points on the bed. First 3 are fine, but once the printer wants to continue, the bed "gets stuck" and the program is aborted (claiming that the sensor didnt trigger, but I guess its due to the missing point it wont reach). By "gets stuck" I mean: the bed moves towards me, a noise appears and the bed instantly stops. I tried it several times and the distance the bed moves before it stops varies a little bit.
-The same happens when I try to run the Calibration.gcode. - I guess its because the mesh bed leveling is done before the calibration print is done.
-I dont know if this is part of the problem, but when moving the Bed by hand its not moving completely free. Its because the Y-axis motor is preventing it. Only with a bit force you can keep moving, but then its easy to move till the next point where the y-axis motor prevents it. Is this normal? In the videos for beginners, the bed can be moved without this "stopping points".
Still when running any other program to calibrate the printer, the bed moves without any disturbance.
What I´ve done to fix the problem:
-Checked to see if the belt slips on the y-axis motor --> No
-Checked if the y-axis pulley slips on the shaft --> No
-Watched the Calibration to see if all points trigger the PINDA probe --> Yes
Here is a short video I´ve made, sorry for the shakey recording. I can rerecord it, if necessary.
Cheers and happy printing,
Nils
Re: Mesh Bed Leveling Fails - Bed gets stuck
If you take away the Y belt, does the bed move by hand in all range from front to back freely with almost no effort?
Re: Mesh Bed Leveling Fails - Bed gets stuck
If you take away the Y belt, does the bed move by hand in all range from front to back freely with almost no effort?
yes - it moves complete free. Its not about the rods. It because of the y-axis motor.
I´m starting to think that his might be a software issue rather than a hardware.
Re: Mesh Bed Leveling Fails - Bed gets stuck
Try to losen Y belt a bit.
Re: Mesh Bed Leveling Fails - Bed gets stuck
Nils
Can you please upload a photo of your Y motor, showing the pulley position on the motor spindle?
Thanks
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Mesh Bed Leveling Fails - Bed gets stuck
Try to losen Y belt a bit.
Before I´ll do it could you please explain, why this might help?
Thanks
Nils
Can you please upload a photo of your Y motor, showing the pulley position on the motor spindle?
Thanks
Peter
See attachments
Re: Mesh Bed Leveling Fails - Bed gets stuck
Before I´ll do it could you please explain, why this might help?
Sure.
My kit come with one of the pulleys a bit excentric (manufacturing error). I realized that after assembly, when I tightened the belt quite much and got into trouble moving the bed by hand. It periodically got stuck because excentric pulley induced a lot of tension. Losening the belt by one tooth solved the problem.
Looking at your picture I can see your pulley it quite close to the motor. Make sure there is enough clearance between the pulley and motor body.
Re: Mesh Bed Leveling Fails - Bed gets stuck
Looking at your picture I can see your pulley it quite close to the motor. Make sure there is enough clearance between the pulley and motor body.
Yup, that's why the photo. You need to move the motor a couple of mm further away from the centre and allow the pulley to move away from the motor body.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Mesh Bed Leveling Fails - Bed gets stuck
Why? Because the pully is grinding against the stepper motor? Or further missalignment the further end ie the idler. Perfectly square and alignment works out of the box. My MK2 is perfectly squarly aligned.
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: Mesh Bed Leveling Fails - Bed gets stuck
Why? Because the pully is grinding against the stepper motor?
Yes, most likely.
Perfectly square and alignment works out of the box.
Well, Nils got dozens of parts out of the box and had to assemble it himself first. 😉 Not everyone buys assembled printer.
Re: Mesh Bed Leveling Fails - Bed gets stuck
Good Morning PJR and David,
Indeed moving the pulley further away from the shaft was the problem. I´ve also loosened the belt a bit, but I assume that the pulley was a problem, since I´ve seen some friction traces on the y-axis motor where the pulley sits.
Next thing which I´m going to do is to tell the Prusa team to mentioned that properly on the assembly guide. I assume that the perspective of the images may assume that the pulley needs to be complete down the shaft.
See Step 29,32,35 (pulley down) - its almost alternating with the other pictures with step 27,32 (pulley middle)
http://manual.prusa3d.com/Guide/2.+Y-axis+assembly/104
Thank you for your kind help I was allready questioning my skills of reading a book,
See you and happy printing
Nils
Re: Mesh Bed Leveling Fails - Bed gets stuck
I think that image on step 34 is quite expressive about pulley position. 😉